Self-rotating projectile.



Patented oct. 17,191.6.

INI/E? ANDRW m. corral, or NEW Yonx, N. Y. l

ySELF-Rorlmrive Pnomc'rrnn.

Specification of Letters Patent.

Patented oct. 17, 191e.

Application led October 11, 1915. Serial No. 55,185.

To all whom t may concern.'

Be it known that. I, ANDREW M. Com, a citizen of the United States, and a resident of New York, county and State of New York, have invented certain new and useful Improvements in Self-Rotating Projectiles, of which the following is a specification, reference being had to the accompanying drawings, forming a part thereof.

it has special reference to such as are adapted to be rotated without the necessity of rifling the gun.

One object of my invention is to provide a projectilethat shall be adapted to be dis- V charged from a smooth bore gun and which shall'embody 'means for producing a rapid rotation of the projectile about its longitudinal axis, such means being active only while the projectile is traversing the length of the gun barrel.

Another object is to provide a projectile that shall be adapted to pass through the air with the least possible resistance, its rear end being specially tapered to avoid producing a partial vacuum in its wake.

Another object is to provide a projectile having means for producing its rotation, comprising a particularly advantageous arrangement of tangential pockets containing quick-burning powder held in place by simple and desirable caps and opening into an annular space formed by a reduced section of the projectile, whereby the powder may be discharged and the resulting forces exerted'while the projectile is in the gun, against the powerful reaction of the compressed gases produced by the main charge of the gun.

I am aware that a rotative movement of a rocket or the like has hitherto been produced by a tangentialdischarge of explosives while the rocket is traveling through the air at a rapid rate, but such an arrangement would 45 be entirely impracticable for rotating a projectile while it is traveling through the air 'after it has been discharged from the muzzle of the gun, because it would be impossible j..

j to produce a pluralityv of absolutely balanced i tangential forces which would have no iniuence upon the projectile itself, except to produce rotation.

action'were exerted upon the projectile, its

.course would be materially altered and the *accuracy of the shot entirely destroyed.

My invention relates to projectiles andA Furthermore, the reactionof the atmosphere is small and the eect of charges of permisthe projectile is obviously held true by the l gun and since, in accordance with my inven-v tion, the tangential discharge is completely tired, while the projectile is stillin the gun and against the reaction of highly compressed gases the objective result is secured, viz., the projectile is rotated at a high speedas it leaves the muzzle of the gun although the gun is smooth bore. f

Another advantage of my arrangement arises from the fact that the tangential .discharges are so `placed relative to the length of the projectile as to assist the main firing charge of the gun.

Other objects and advantages of my invention will be set forth hereinafter, and in order that my invention may be thoroughlyA understood I will now proceed to describe the vsame in the following specification and then point out the novel features thereof in appended claims.

Referring to the drawings: Figure I is a longitudinal elevation of a projectile embodying my invention, mounted in a gun, a portion of which is shown in section. Fig. 2 is a transverse sectional elevation, taken 011 the line 2 2 of Fig. 1. Fig. 3 showsa single tangential discharge pocket drawn to a much larger scale. Fig. 4 shows the cap, which is located in the mouth of the pocket, in front elevation.

The projectile illustrated is designated by the reference numeral 10 and has its front end tapered to a point in the usual manner, as shown at 11. The rear end lof the pro- Obviously, if any otherjecti le is formed into a tapered section 12 and hasa curved or rounded end 13 of relatively small radius. The larger end of the tapered section l2 oins the cylindrical central section of the projectile by curves as indicated at 14. Near the larger end of the tapered section where the cross-section 2--2 is taken, the projectile is provided with a plurality of pockets 15-15 and 16-16 which are arranged in pairs, the pockets of each pair -beingat equal distances on opposite sides of the 'center and having their discharge ends at diametrically opposite points inthe circumference of the circular section formed by the intersection of a transverse plane and the projectile. Y

The pocketsare not necessarily arranged in pairs as any number may be employed. I prefer, however, that the forces exerted shallbe substantially balanced relative to the axis of the projectile. is closed at'its inner end and is loaded with a`suitable charge of quick-burning powder or other explosive. The charge with which the gun is loaded in the usual manner, comprises a relatively slow-burning explosive material, the result being that lthe tangential chargesare fired and the reaction of the tangential charges which takes place while the projectile is'in the gun, produces a high-speed rotation of the projectile. Furthermore, the explosive gases formed by the discharge of the tangential charges are added to, and act in conjunction with, the explosive gases resulting from the main discharge. n

As above indicated, the direction of the projectile is absolutely maintained by bore of the gun, and since the tangentialA discharges are not active, after the projectile leaves the muzzle of the gun', they have no tendency to interfere in any way with the accuracy of the shot.

`Attention is particularly directed to the fact that the tangential dischargeV pockets are located in a transverse plane, which is near the rear of the projectile, and in the tapering section thereof, thereby producing a suitable spiace in which the explosive gases may be discharged.

While I prefer to have the rear'of the projectile tapered since the best results are obtained/in this way, my invention is not limited in this regard and the rear of the projectilemay be reduced in size to provide the annular space 23 into which the tangential pockets are discharged. The pockets are preferably loaded with loose quick-burns ing powder to insure a very rapid action.

The tangential pockets may be closed in any suitable manner after thel explosives are in placa-for example, the projectile at the mouth of each pocket may be provided with grooves'l9 tovreceive a.cap.20. This may comprise a pair of washers or perforated disks 21 of thick paper or cardboard between which is held a thin sheet 22 of oil or paraffin paper. The capv may be formed in some other suitable manner so long as it is adapted to be instantly destroyed when Each ofthe pockets l the main charge is fired in the gun, thereby I insuring that the quick-firing charges in the pocket are exploded. v-

The body of the vprojectile at themopthwmv of the pockets is cut away, curved, or 'shaped 70 as indicated at 24, to provide ready dis-- charge paths for the gases from the pockets into the annularspace 23.

Strictly, the pockets cannot be tangentially disposed or discharge tangentially "relative to the surface of the projectile but producing rotation the pockets are described as tangential The projectile of my invention is particularly advantageous because not only is -its rear end so tapered as to reduce the friction and windage losses to a minimum, but also the same tapering provides the annular space into which the explosive in the tangential pockets discharge. The reduction in friction and the elimination vof the partial vacuum at the rear increases the flight lof theqprojectile .by 'a'large percentage and this is' further increased by the fact. that the retardation due to the gun reexing, is

- avoided. A projectile of superior eficiency and effectiveness Ais therefore produced. What I claim is:

1. A uprojectile having a cylindrical body and a. tapered rear end, a plurality of tangential discharge pockets having openings in the tapered rear end, quick-firing explosives therein, and caps for holding the explosives in position, said explosives being adapted to be fired by the explosion of the gun charge, whereby' a rotation ofthe -projectile is produced while the projectile is in the gun.l

2. A projectile having a reduced section` to provide an annular space at the rear, a plurality ofA tangential' discharge pockets opening into said space, and ,quick-burning powder in said pockets. u y

3. A projectile having a reduced section to -provide an annular space at the rear, a plurality of tangential discharge pockets opening into said space, quick-burning powder in said pockets, and means, adapted to be disrupted by the gun charge, for holding the quick-firing powder in the pockets.

4. A projectile having a reduced section to provide an annular space at the rear, a plurailty of tangential discharge pockets lopening into said space, quick-burning powder in said pockets, and a cap for each pocket comprising relatively stiff perforated sheets and a thin iilm' between them.

5. A projectile having a reduced `section to provide an annular space at the rear, a plurality of tangential discharge pockets, opening into said space, quick-burning powder in said pockets, andacap foreach pocket comprising relatively stiff washers in said pockets, and a cap for each pocket and a thin sheet of fabric stretched between comprising perforated cardboard sheets and the washers. a thin sheet of paraiin paper sealed between 13 6. A projectile having a reduced section to them. 5 provide an annular space at the rear, a plu- In witness whereof, I have hereunto set rality of tangential discharge pockets openmy hand this 7 day of October, 1915. ing into said space, quick-burning powder ANDREW M7 COYLE. 

